User impersonation for Appwrite Auth

Trusted operators can now impersonate users in Appwrite Auth to reproduce issues, validate permissions, and provide hands-on support without sharing credentials.

This release adds a new impersonator capability on users, available from the Appwrite Console and the Users API, plus direct SDK support for targeting a user by ID, email, or phone.

Impersonated requests still begin from a real authenticated user session, and internal audit logs continue to attribute actions to the original impersonator while recording the impersonated target in internal audit payload data.